利用辉光等离子渗金属技术,在低碳钢Q235表面进行钨钼钇共渗,研究了极间距、保温温度、气压、保温时间对渗层厚度的影响,进而确定最优工艺参数,并对渗层的金相组织、合金元素分布及物相组成进行分析。结果表明:极间距25mm、保温温度1000℃、工作气压30Pa、保温时间3h为最优参数,所得渗层的厚度可达37μm;渗层组织为柱状晶,渗层与基体有一明显分界线;钨、钼在渗层中呈梯度分布,钇在渗层中呈不均匀分布并在晶界处发生偏聚。

Low carbon steel Q235 was firstly conducted by W-Mo-Y double glow plasma surface alloying process.Then the optimal process parameters were confirmed by means of researching the effects of electrode distance, working pressure, holding time, and holding temperature on the thickness of alloying layer. And Optical morphologies, alloying elements distribution and phase composition were analyzed. The results show as follows: the optimal process parameters of W-Mo-Y surface alloying process are as follows: interelectrode distance 25 mm, working pressure 30 Pa, holding time 3 h, holding temperature 1000 ℃. The thickness of alloying layer can reach 37 μm; The microstructure of alloying layer is columnar crystal, and there is anobvious boundary between alloying layer and the matrix. And W and Mo in alloying layer are in gradient distribution. Y is not evenly distributed, and segregate at grain boundaries.